It is known the current digital audio broadcasting (DAB) transmission technique is different from the conventional amplitude modulation (AM) and frequency modulation (FM) broadcasting techniques. By DAB, digital signals from satellites or terrestrial transmitting stations can be received via an antenna that is connected to a multimedia device, so as to achieve the purpose of broadcasting and improving the drawbacks in the conventional broadcasting techniques, including poor sound quality, easily interfered radio signals, and broadcasting quality easily affected by transmission power.
While the current DAB technique can improve the drawbacks in the conventional broadcasting techniques, it has the problems of having a bulky digital broadcasting antenna and being restricted to a fixed signal receiving direction. As a result, the current DAB technique has relatively poor signal receiving quality, insufficient bandwidth and high return loss.
It is therefore desirable to develop an improved digital broadcasting antenna structure capable of achieving the effects of high bandwidth and low return loss.